5-in-1 board failure, loss of control, & the chicken dance-- PHOTOS

[hydro_pyro]

The mSR is just about the most fun I've ever had with anything of this type. However, I believe there is a known issue with the mSR's 5-in-1 board. It is a fragile, lightweight component, with surface-mounted electronics and servos on one small board, mounted by two screws. Production mSR's have a thin bead of epoxy around the perimeter of the two square chips on the front of the board. mSR's which have been subject to physical stresses tend to flex along a specific part of the board, particularly across the lower outside corner of the square chip nearest to the antenna wire. This stress causes solder joints at this chip to fail, usually resulting in loss of bind, fly-away with loss of ALL Tx control, intermittent operation, or total failure. The board may also cut in-and-out when you press gently against the edge. If your heli crashes and does the chicken dance on a freshly charged battery, or flies away completely out of control, this is probably the cause. I have now personally lost FIVE of these boards since December '09, and upon inspecting recent failures up-close, I believe at least three of them failed in the same exact fashion. A stress crack in the epoxy is visible to the naked eye. I put #4 and #5 on my scanner to show the trouble area, marked by a yellow line in the first photo...



Take a closer look-- I sent in this board for warranty service today.



Here's the other one I sent in, this one failed after two batteries. See the similarity?



So far, Horizon has covered these for me under warranty. Thus, I continue to help them sell lots of mSR's with my personal recommendations, based heavily upon their great customer service. Thanks Horizon!

[hydro_pyro]

Watch this pilot's video clips. These are the symptoms of the problem described above...

YouTube

YouTube

Watch how the 5-in-1 springs back to life when he touches it with his finger at 0:22...

YouTube

YouTube

[n7ki]

Had the same exact problem with my 5-in-1 board and had to call Horizon twice to get them to replace it. First time they said so sorry. Called and talked to someone else the next day and after complaining about issues like infant mortality and other things, they finally said they would send me a replacement but they stated that there would be no additional warranty on my mSR.
It's hard to believe that they pc board material (looks like FR4 fiberglass) is cracking. I would under stand that if it was phenolic board material. I will not argue that it is happening though because I could put my thumb and index finger on the bottom of the pc board and squeeze and it would work ok until the next serious crash. This does appear to be a known problem and I would think they should be proactive in fixing the problem other than just replacing the board. There should only be two items on the board that are crash sensitive and they are the gyro and the crystal associated with the receiver. The rest should be bulletproof.

I would like to know how you get such good service. I think they should come out with the board without the servos and lower the price. I know how to solder.

[hydro_pyro]

It's not a crack in the board itself, but rather a concentrated area of flex and stress in an area of the board which cannot tolerate those forces due to component locations. The board normally flexes a tiny bit. Ideally, the flex is uniform. In the mSR's case, there's two mounting holes, and two IC chips that do NOT flex, which also have very small solder points. The elevator servo's motor is at the edge of the board (far away from center) and provides the equivalent of a weight on the end of a lever in terms of mass and interia in a mild crash. Additionally, the servos themselves receive vibrating forces from the cyclic linkages during normal operation, which must be absorbed by the board. This integrated design seems to work well in lightweight micro planes where forces are minimal, but this design is pushed beyond its mechanical limits in the mSR, in my opinion. The fact that they put epoxy around the chip already indicates to me that the design team was likely aware of the potential for mechanical failures of these solder joints.

A guy on RCG from Denmark who works on cell phones for a living claims that he was able to fix his failed 5-in-1 board. He removed the epoxy with a fine-tip regulated heat gun and a toothpick, and re-flowed the chip's solder joints with a needle point soldering iron, under a microscope. Very impressive...

[Loose Nut]

I wonder if you could reball the joints ?
as in heat them in the oven or use a heat gun

if HH says no more warranty after a 5in1 replacement

[hydro_pyro]

Uhh, like I just mentioned above, a guy on another forum reported having successfully re-flowed the solder joints on his bad 5-in-1 to bring it back to life.

[twofieros]

Nice report Hydro. Good to know about these flaws and potential fixes. I still don't see how you get horizon to replace your boards. With that one that broke on me I did what you said and complained. I actually did it three times because I never got the automatic response from the first two attempts. Then apparently all three went through and it turned into a review of their customer service. Of the three emails I sent, all the same by the way, the first one said they would send me a new 5n1 this time but never again. This first one went on to say he liked my email as he owned an 1987 Fiero GT when he was younger. So, did I get that replaced because the guy felt he could relate to me? Second one said I needed to send the 5n1 to them for repair. Third said it wasn't covered and there was nothing they could do for me. I chock all that up to being a 50/50 chance to get a new 5n1. Potentially 66/33 for a new board if I sent in one. I'm not going to send it in because I'm already getting a new board. I just want one.

I should get all I can as it turned out my B400 was crashing all the time from the transmitter. Now I got that fixed I flew 5 batteries yesterday back to back without a crash. I knew it wasn't me!

[Aecium]

This thread was a great help, I was flying just fine around my house last Friday, and then when I went to fly again on Saturday my MCX took off and went right to the ceiling and stuck there for a good 10 seconds before responding to the remote again, and then it stopped binding. After hours of messing around and searching, I found this thread, and found that if I put a bit of pressure on my 5in1 it would work. I sent an message to horizon on Saturday and they got back to me today telling me they would replace my 5in1 this time =-) made me a very happy customer.

[EQMOD]

i usually repair mine using a 'heated knife edge'. That is if the pins of a surface mount chip gets detached from the board, i just put sharp edge of a knife or a cutter on top of those pins and heat that part of the knife with a low wattage soldering iron just enough to melt the solder.

At some point i also do my 'solder quality inspection' with a DIY macro cam pictures (ordinary cam with the lens reversed) and see if the components are properly soldered or if there are any cold solder joints.







Even coils are prone to 'small' issues;

[hydro_pyro]

Thanks to Lucid for hooking me up with your old 5-in-1 with broken motor connectors and servos a while back. It will come in very handy when I move the good parts onto it and re-build. Thank you!

After a serious high-speed crash to the pavement this evening, I have now have the special honor of having broken SIX 5-in-1 boards. After re-trimming the bird, it started randomly freezing all control values mid-flight, the classic "chicken dance" symptom. As expected, this one sustained a crack in the chip epoxy, but this time it was the other chip, since the crash involved a left-hand bank turn Look near the upper left corner of the chip on the right...

[BaconRaygun]

SIX 5 in 1's! Dude, horizon should send you a free mSR just because you really put this thing through its paces... Or hire you as a 'test pilot' or something.

[hydro_pyro]

I sure hope Horizon has learned something from all the testing, modifying, flying, and reporting I've done on the mSR.

I'm sure I have more flight time on the bird than their entire design team combined.

[BaconRaygun]

Originally Posted by hydro_pyro

I sure hope Horizon has learned something from all the testing, modifying, flying, and reporting I've done on the mSR.

I'm sure I have more flight time on the bird than their entire design team combined.

Yeh man I wouldn’t be surprised if you do... You would think that they have somebody scanning the forums to see what people say about and do with the mSR but seems doubtful. Seems like if they did they would be on the winning end because were the ones spending time and money doing the R&D for them.

[rccopter]

This info was great. Yesterday I was pulling out of a dive but mis-judged and nailed a curb head on, full throttle. After that the 5-in 1 would only flash quickly. Re-binding did nothing. Then I read your thread. Pressing on the corner of the afore mentioned surface mounted IC would allow it to initialize. Using a head worn magnifier along with my magnified bench light I scrapped the epoxy off the IC and re-flowed the surface connections with a soldering iron ground down to a point. It now works great!
Thank's for the tip on this failure.



Rick

[EQMOD]

i was also a victim of a 'randomly' binding 5-in-1 but was not able to locate the crack point. LHS says the 5-in-1 would be available in a month's time thus went to the walkera 4-in-1 swap route instead. She is much better now in servo, tail, and throttle response. None of those dead stick response close to the stick center and that funky rudder-elevator mix. What is that purpose of that mix anyway ? for stable piros ?



I simply recycled the servos of the 5-in-1 and trimmed the unnecessary components;

But wait! I even attempted to trim and remove the surface mount microcontroller and 2.4ghz cypress module out of the board to keep things light as this was piggybacked with the walkera 4-in-1. The ICs are practically glued on the board.The board is too thin. Any flexure on the board ( resulting from crash) would take "glued" copper patterns away from the board.

[rccopter]

Nice! Are there instructions somewhere on how to do this? I did a quick search but did not find any.

Thanks.

Rick

[reefboy]

Thanks hydro_pyro! Because of this posting I successfully repaired my 5 in 1.
I did the following:

• Used a low wattage soldering iron with an exacto #11 blade to remove as much of the epoxy as possible using a stereo zoom microscope.
• Cleaned it up with IPA and did a 2nd round of cleaning of epoxy using the heated exacto blade
• Used a water clean flux pen and hit one edge of pins
• Fitted the low wattage soldering iron with a small soldering tip
• Quickly touch the end of the soldering iron on each pad.
• I would reapply the flux after touching 3 consecutive pads

All in all I probably spent 40 minutes. I would say there is no possible way of doing it w/o using a good stereo zoom microscope. One row of pins looked poor as I ran out of patient removing the epoxy. This is the first time I have attempted something like this so my skills are not good and some of it looked bad. However, even with that being said the heli is flying great. I was having quite a bit of fun with it and crashed a few times and everything has held up just fine. Time to try the repair on another board I have.

[k_ogre]

my son gave me his and it's doing the same thing don't think i can get a replacement w/o sales slip but this sounds like a known defect and should be recalled. at 60.00 a pop that can add up can you say class action lawsuit lol

[hydro_pyro]

Using terms like "class action" and "recall", you make it sound like it's a consumer safety issue.
With all due respect, this is NOT even a "defect" issue--
It's something that happens when you crash it into the ground at high speed.
Are you expecting the warranty to cover crash damage?
If you drive your Ford Explorer with four flat tires and a tread comes off, whose fault is that?

[CocoSantango]

I think since it's considered a model and not a toy, they're also well covered.